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epiR (version 2.0.75)

epi.about: The library epiR: summary information

Description

Tools for the analysis of epidemiological data.

Usage

epi.about()

Arguments

FUNCTIONS AND DATASETS

The following is a summary of the main functions and datasets in the epiR package. An alphabetical list of all functions and datasets is available by typing library(help = epiR).

For further information on any of these functions, type help(name) or ?name where name is the name of the function or dataset.

For details on how to use epiR for routine epidemiological work start R, type help.start() to open the help browser and navigate to Packages > epiR > Vignettes.

CONTENTS:

The functions in epiR can be categorised into two main groups: tools for epidemiological analysis and tools for the analysis of surveillance data. A summary of the package functions is as follows:

I. EPIDEMIOLOGY

1. Descriptive statistics

epi.confConfidence intervals.
epi.descriptivesDescriptive statistics.

2. Measures of health and measures of association

epi.directadjDirectly adjusted incidence rate estimates.
epi.edrCompute estimated dissemination ratios from outbreak event data.
epi.empbayesEmpirical Bayes estimates of observed event counts.
epi.indirectadjIndirectly adjusted incidence risk estimates.
epi.insthazInstantaneous hazard estimates based on Kaplan-Meier survival estimates.
epi.2by2Measures of association from data presented in a 2 by 2 table.

3. Diagnostic tests

epi.betabusterAn R version of Wes Johnson and Chun-Lung Su's Betabuster.
epi.herdtestEstimate the characteristics of diagnostic tests applied at the herd (group) level.
epi.nomogramCompute the post-test probability of disease given characteristics of a diagnostic test.
epi.pooledEstimate herd test characteristics when samples are pooled.
epi.prevCompute the true prevalence of a disease in a population on the basis of an imperfect test.
epi.testsSensitivity, specificity and predictive value of a diagnostic test.

4. Meta-analysis

epi.dslMixed-effects meta-analysis of binary outcome data using the DerSimonian and Laird method.
epi.ivFixed-effects meta-analysis of binary outcome data using the inverse variance method.
epi.mhFixed-effects meta-analysis of binary outcome data using the Mantel-Haenszel method.
epi.smdFixed-effects meta-analysis of continuous outcome data using the standardised mean difference method.

5. Regression analysis tools

epi.cpExtract unique covariate patterns from a data set.
epi.cpresidsCompute covariate pattern residuals from a logistic regression model.
epi.interactionRelative excess risk due to interaction in a case-control study.

6. Data manipulation tools

epi.ascWrite matrix to an ASCII raster file.
epi.convgridConvert British National Grid georeferences to easting and northing coordinates.
epi.dmsConvert decimal degrees to degrees, minutes and seconds and vice versa.
epi.ltdCalculate lactation to date and standard lactation (that is, 305 or 270 day) milk yields.
epi.offsetCreate an offset vector based on a list suitable for WinBUGS.
epi.RtoBUGSWrite data from an R list to a text file in WinBUGS-compatible format.

7. Sample size calculations

The naming convention for the sample size functions in epiR is: epi.ss (sample size) + an abbreviation to represent the sampling design (e.g., simple, strata, clus1, clus2) + an abbreviation of the objectives of the study (est when you want to estimate a population parameter or comp when you want to compare two groups) + a single letter defining the outcome variable type (b for binary, c for continuous and s for survival data).

epi.sssimpleestbSample size to estimate a binary outcome using simple random sampling.
epi.sssimpleestcSample size to estimate a continuous outcome using simple random sampling.
epi.ssstrataestbSample size to estimate a binary outcome using stratified random sampling.
epi.ssstrataestcSample size to estimate a continuous outcome using stratified random sampling.
epi.ssclus1estbSample size to estimate a binary outcome using one-stage cluster sampling.
epi.ssclus1estcSample size to estimate a continuous outcome using one-stage cluster sampling.
epi.ssclus2estbSample size to estimate a binary outcome using two-stage cluster sampling.
epi.ssclus2estcSample size to estimate a continuous outcome using two-stage cluster sampling.
epi.ssxsectnSample size, power or detectable prevalence ratio for a cross-sectional study.
epi.sscohortcSample size, power or detectable risk ratio for a cohort study using count data.
epi.sscohorttSample size, power or detectable risk ratio for a cohort study using time at risk data.
epi.ssccSample size, power or detectable odds ratio for case-control studies.
epi.sscompbSample size, power and detectable risk ratio when comparing binary outcomes.
epi.sscompcSample size, power and detectable risk ratio when comparing continuous outcomes.
epi.sscompsSample size, power and detectable hazard when comparing time to event.
epi.ssequbSample size for a parallel equivalence or equality trial, binary outcome.
epi.ssequcSample size for a parallel equivalence or equality trial, continuous outcome.
epi.sssupbSample size for a parallel superiority trial, binary outcome.
epi.sssupcSample size for a parallel superiority trial, continuous outcome.
epi.ssninfbSample size for a non-inferiority trial, binary outcome.
epi.ssninfcSample size for a non-inferiority trial, continuous outcome.
epi.ssdetectSample size to detect an event.
epi.ssdxsespSample size to estimate the sensitivity or specificity of a diagnostic test.
epi.ssdxtestSample size to validate a diagnostic test in the absence of a gold standard.

8. Miscellaneous functions

epi.prccCompute partial rank correlation coefficients.
epi.psiCompute proportional similarity indices.
epi.realriskReturn absolute risks from odds, incidence risk and hazard ratios.

9. Data sets

epi.epiduralRates of use of epidural anaesthesia in trials of caregiver support.
epi.incinLaryngeal and lung cancer cases in Lancashire 1974 - 1983.
epi.SClipLip cancer in Scotland 1975 - 1980.

II. SURVEILLANCE

Below, SSe stands for surveillance system sensitivity. That is, the average probability that a surveillance system (as a whole) will return a positive surveillance outcome, given disease is present in the population at a level equal to or greater than a specified design prevalence.

1. Representative sampling --- sample size

rsu.sspfree.rsDefined probability of disease freedom.
rsu.sssep.rsSSe, perfect test specificity.
rsu.sssep.rs2stSSe, two stage sampling.
rsu.sssep.rsfreecalcSSe, imperfect test specificity.
rsu.sssep.rspoolSSe, pooled sampling.

2. Representative sampling --- surveillance system sensitivity and specificity

rsu.sep.rsSSe, representative sampling.
rsu.sep.rs2stSSe, representative two-stage sampling.
rsu.sep.rsmultSSe, representative multiple surveillance components.
rsu.sep.rsfreecalcSSe, imperfect test specificity.
rsu.sep.rspoolSSe, representative pooled sampling.
rsu.sep.rsvarseSSe, varying surveillance unit sensitivity.
rsu.spp.rsSurveillance system specificity.

3. Representative sampling --- probability of disease freedom

rsu.pfree.rsProbability of disease freedom for a single or multiple time periods.
rsu.pfree.equEquilibrium probability of disease freedom.

4. Risk-based sampling --- sample size

rsu.sssep.rbsrgSSe, single sensitivity for each risk group.
rsu.sssep.rbmrgSSe, multiple sensitivities within risk groups.
rsu.sssep.rb2st1rfSSe, 2 stage sampling, 1 risk factor.
rsu.sssep.rb2st2rfSSe, 2 stage sampling, 2 risk factors.

5. Risk-based sampling --- surveillance system sensitivity and specificity

rsu.sep.rbSSe, risk-based sampling.
rsu.sep.rb1rfSSe, risk-based sampling, 1 risk factor.
rsu.sep.rb2rfSSe, risk-based sampling, 2 risk factors.
rsu.sep.rbvarseSSe, risk-based sampling, varying unit sensitivity.
rsu.sep.rb2stSSe, 2-stage risk-based sampling.

6. Risk-based sampling --- probability of disease freedom

rsu.pfree.equEquilibrium probability of disease freedom.

7. Census sampling --- surveillance system sensitivity

rsu.sep.censSSe, census sampling.

8. Passive surveillance --- surveillance system sensitivity

rsu.sep.passSSe, passive surveillance.

9. Miscellaneous functions

rsu.adjriskAdjusted risk values.
rsu.dxtestSeries and parallel diagnostic test interpretation.
rsu.epinfEffective probability of disease.
rsu.pstarDesign prevalence back calculation.
rsu.sepProbability disease is less than specified design prevalence.

Author

Mark Stevenson (mark.stevenson1@unimelb.edu.au), Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville Victoria 3010, Australia.

Evan Sergeant (evansergeant@gmail.com), Ausvet Pty Ltd, Level 1 34 Thynne St, Bruce ACT 2617, Australia.

Simon Firestone, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville Victoria 3010, Australia.

Telmo Nunes, UISEE/DETSA, Faculdade de Medicina Veterinaria --- UTL, Rua Prof. Cid dos Santos, 1300 - 477 Lisboa Portugal.

Javier Sanchez, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown Prince Edward Island, C1A 4P3, Canada.

Ron Thornton, Ministry for Primary Industries New Zealand, PO Box 2526 Wellington, New Zealand.

With contributions from: Cord Heuer, Jonathon Marshall, Jeno Reiczigel, Jim Robison-Cox, Paola Sebastiani, Peter Solymos, Yoshida Kazuki, Geoff Jones, Sarah Pirikahu, Ryan Kyle, Johann Popp, Methew Jay, Allison Cheung, Nagendra Singanallur, Aniko Szabo and Ahmad Rabiee.

Details

More information about the epiR package can be found at https://mvs.unimelb.edu.au/research/groups/veterinary-epidemiology-melbourne and https://www.ausvet.com.au/.